One or more embodiments of the subject matter described herein relate to data communications and, more particularly, to data communications with a rail vehicle.
Rail vehicles such as distributed power trains include a lead powered unit, such as a locomotive, (lead unit) and one or more remote powered units, such as other locomotives, (remote units), dispersed through out the train. These powered units supply the tractive effort to propel the train along a track. For distributed power operations, the lead and remote locomotives may communicate with each other to coordinate the tractive efforts and/or braking efforts provided by each locomotive. For example, a lead or first locomotive may communicate with a remote or second locomotive of the same train in order to control or otherwise direct how much tractive effort the second locomotive is to provide based on the terrain, the grade of the track, emission restrictions, amounts of cargo being transported by the train, and the like.
Some known powered units in distributed power trains wirelessly communicate with each other. For example, lead and trailing locomotives in distributed power trains can wirelessly communicate data signals with each other. The powered units may be assigned a communication channel over which data signals are communicated. The communication channel may be defined as a frequency or band of frequencies used to wirelessly communicate the data signals.
The channels may be assigned to the distributed power trains based on a unit identification or serial number (S/N) of one or more of the powered units of the distributed power train. For example, the distributed power train having a locomotive with a unit identification or serial number (S/N) ending with “1” are assigned a first channel, the distributed power train having a locomotive with a unit identification or serial number (S/N) ending with “2” are assigned a different second channel, and so on. The amount of available channels for assignment among the powered units may be limited by statutory and/or regulatory restrictions.
In geographic areas that are densely populated with many distributed power trains, several distributed power trains each having multiple powered units may be assigned to the same channel. As more distributed power trains are assigned to a common channel, the communication of data signals between the powered units of each distributed power trains may be significantly delayed. As a result, an instruction to change a tractive effort that is sent by the lead powered unit to the remote power units in the same distributed power trains may not be delivered in time in order to coordinate the tractive efforts provided by the powered units.
A need exists for an improved system and method for communicating within and/or among rail vehicles.